On May 7th, in an election in Britain, the pre-election polls showed conservatives would win around 280 seats. The exit polls during the election showed the conservatives would win around 316 seats. During the election, conservatives actually won 330 seats.

In 1992, also in Britain, the pre-election polls showed the conservative and liberal parties in a dead heat. The conservatives actually won by 7.5 points.

In the recent election in Israel, Likud was predicted, through polling, to win 22 seats. Likud actually won 30 seats.

These aren’t random events — they are repeated time and again in elections through the last decade or so. Sociologically, one explanation for the difference between the polls and the results is that in cultures where being conservative is seen as socially unacceptable, people simply tell the pollster what they think the pollster wants to hear — they tell them what they think will make them liked, or at least accepted.

In other words, people are capable of lying. Don’t sit there with a stunned look on your face, as if you’d never thought of this before.

I know polls are one thing, and big data is another. The Internet of Things is, after all, going to put sensors in every home, at every street corner, in every car, and in every piece of electronics you might encounter in your daily life. Then you won’t have the ability to lie, because all sharing will be frictionless.

People don’t always like to be “nudged,” and they’re pretty good liars, if you want to know the truth. Kids posting the names of songs on social media sites that describe how they feel — knowing their parents don’t know the song, and hence won’t get the point. Jokes about squirrels and blue dories. Winston keeping a dairy outside the range of the all seeing eye of Big Brother — people will find a way to communicate and remember no matter what measures you might take.

And if you think the solution to this problem is “just add more sensors,” then I find your line of thinking pretty creepy.

But this is the bottom line problem with data analytics — we can’t really measure intent, just action. We can try to infer intent from action, but people are pretty good at doing one thing, and meaning another — especially once they figure out how you’re measuring them.

So before we go running off into a world of, “ignore your common sense, and use the data, Luke,” we might need to think about this little problem called humanity. Or maybe it’s time to inject a little reality and humility into our way of thinking.

Maybe we really can’t “solve the world’s problems.” Maybe we can’t influence people to do what we think is best all the time, no matter how much data we covet and collect and hoard and analyze. And maybe, by focusing so hard on this, we’re like the statistician who’s ignoring his head slowly roasting.